pub fn dp_rec_mc(amount: u32) -> u32 {
    // TODO: 这里写逻辑
    // 贪心
    // 从最大面额的纸币开始，尽可能多的找零，直到无法找零为止
    let cash = [100, 50, 30, 20, 10, 5, 2, 1];
    let mut remaining = amount;
    let mut cash_count = 0;
    for &c in &cash {
    	if remaining == 0 {
    		break;
    	}
    	let count = remaining / c; // 计算需要该面额纸币的数目
    	cash_count += count;
    	remaining %= c; // 计算剩余的钱 
    }
    cash_count
}
